JP2015058566A - Vacuum molding apparatus and resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum molding apparatus capable of molding light and high-strength ribs erected integrally with a base part and a resin molding.SOLUTION: A vacuum molding apparatus 20 includes a molding die 20g which transfers a moldable resin sheet 30 and molds, a rib molding portion 20j provided with two hollow pipes 20f which are erected in the bottom part of the molding die 20g at a specified interval in such a way as to penetrate the bottom part vertically and a wire 20i which is inserted into the hollow pipes 20f and bridged between the upper ends of the individual hollow pipes 20f and a vacuum pump 25 which transfers the resin sheet 30 set in the molding die 20g to the molding die 20g and the rib molding portion 20j. After the resin sheet 30 is transferred to the molding die 20g and the rib molding portion 20j by sucking evacuation with the vacuum pump 25, the wire 20i is drawn out from the hollow pipes 20f.

Description

  The present invention relates to a vacuum forming apparatus and a resin molded product for forming a resin molded product by transferring a resin sheet to a molding die.

  A vacuum molding apparatus is known as an apparatus for integrally molding a resin molded product (see Patent Document 1). The vacuum forming apparatus is an apparatus for forming a resin molded product by adsorbing and transferring a resin sheet to a forming die.

  As a conventional resin molded product, a resin molded product 1 having a structure shown in FIGS. 5A and 5B is known. Fig.5 (a) is a perspective view of the resin molded product 1, (b) is A1-A1 sectional drawing of the resin molded product 1 shown to (a).

  The resin molded product 1 is integrally provided with a box-shaped base portion 1a having an open top surface and a plate-like rib 1b erected perpendicularly to the bottom surface at the center of the bottom surface of the base portion 1a. Furthermore, the rib 1b has a structure in which the plate-like upper side portion 1c is cylindrical, and the columnar metal material 3 is inserted into the cylindrical shape. Thus, in the resin molded product 1, the strength of the rib 1b is increased by incorporating the metal material 3 in the upper side 1c of the rib 1b.

  When the resin molded product 1 is integrally formed with a vacuum forming apparatus, it is considered that the vacuum forming is performed in a state where the metal material 3 is disposed on the upper end of the mold material for forming the rib 1b.

JP 2009-39862 A

  However, since the resin molded product 1 formed as described above has the cylindrical metal material 3 as described above incorporated in the plate-like rib 1b, the strength is improved, but the weight increases accordingly. There was a problem. The heavy resin molded product 1 cannot be used as a component of a device that is required to be light. That is, there is a problem that it is difficult to achieve both improvement in strength and weight reduction of the rib 1b.

  The present invention was created in order to solve such problems, and provides a vacuum molding apparatus and a resin molded product capable of molding a rib standing integrally with a base with light weight and high strength. With the goal.

  In order to solve the above-mentioned problems, a vacuum forming apparatus according to the present invention includes a forming die for transferring and forming a formable resin sheet, and standing vertically through the bottom portion at a predetermined distance from the bottom portion of the forming die. Two hollow pipes to be provided and a rib molding part configured to include wires inserted into the hollow pipes and spanned over the upper ends of the hollow pipes; and the resin sheet set in the molding die And a transfer means for transferring to the rib forming part, and after transferring the resin sheet by the transfer means, the wire is pulled out from the two hollow pipes.

  According to such a configuration, after transferring the resin sheet to the mold, the upper side of the rib formed by the resin sheet molded in the rib molding section is obtained by pulling out the wire from each hollow pipe of the rib molding section standing on the bottom of the mold A hollow space (cavity) where a wire is present is formed in the part. Further, if the cured resin sheet is removed from the mold, the hollow pipes on both sides are pulled out from the ribs formed by the resin sheet, so that a hollow space (cavity) is formed on the side of the rib.

  Thereby, the hollow space (cavity) connected to the side part and the upper side part of the rib is formed and becomes a cylindrical shape. In other words, the central part other than the side part and the upper part of the rib is brought into close contact, and no cavity is formed. Since the cylindrical shape has a large force to resist external pressure, the strength of the rib can be increased. Further, unlike the prior art, no metal material is used and the inside of the rib is hollow, so that the rib can be reduced in weight. Therefore, the rib erected integrally with the base of the resin molded product can be light and high in strength.

  In addition, a release agent is applied to the wire before the wire is inserted through the two hollow pipes.

  According to such a configuration, by applying the release agent to the wire, it becomes easy to insert the wire into each hollow pipe, and when the wire is pulled out, it becomes easy to pull out.

  The apparatus further comprises a temperature adjusting means for heating the mold before transferring the resin sheet to the mold and cooling the mold after the resin sheet is transferred to the mold. .

  According to such a configuration, since the resin sheet is heated before transfer, the resin sheet can be easily molded, and the resin sheet can be quickly adsorbed to the mold and transferred without a gap. Further, if the mold is cooled after the transfer, the resin sheet can be quickly cooled and cured.

  Further, in the resin molded product of the present invention, a base portion and a rib standing on the base portion are integrally formed, and the rib includes a flat plate portion and a pair of side portions formed on both sides of the flat plate portion, A hollow space communicating with the pair of the side portions and the upper side portion is formed.

  According to such a configuration, since no metal material is used as in the prior art, weight reduction can be achieved. Moreover, since the outer peripheral part by the side part and upper side part of a rib is cylindrical, the drag with respect to an external pressure becomes large and the intensity | strength of a rib can be made high.

  According to the vacuum forming apparatus according to the present invention, it is possible to form a resin molded product in which the ribs standing integrally with the base are molded with light weight and high strength. Moreover, according to the resin molded product which concerns on this invention, the rib erected integrally with a base part can be made lightweight and high intensity | strength.

(A) is a perspective view which shows the structure of the resin molded product shape | molded with the vacuum forming apparatus which concerns on embodiment of this invention, (b) is A2-A2 sectional drawing of the resin molded product shown to (a), (c). FIG. 3 is an A3-A3 cross-sectional view of the resin molded product shown in FIG. (A) is sectional drawing of the front side which shows the structure of the vacuum forming apparatus which shape | molds the resin molded product which concerns on embodiment of this invention, (b) is sectional drawing of the side surface side of a vacuum forming apparatus. (A) Side view sectional view showing a state where the resin sheet is set in the vacuum forming apparatus, (b) Side view sectional view showing a process of transferring the resin sheet to the mold, (c) Resin sheet on the mold It is sectional drawing of the side surface which shows the state which transferred. (A) After transfer of the resin sheet, a side sectional view showing a state where the wire is pulled out from the hollow pipe, (b) a side sectional view showing a state where the resin molded product by the resin sheet transfer is removed from the mold. is there. (A) The perspective view which shows the structure of the conventional resin molded product, (b) is A1-A1 sectional drawing of the resin molded product shown to (a).

Embodiments of the present invention will be described below with reference to the drawings.
<Configuration of Embodiment>
Fig.1 (a) is a perspective view which shows the structure of the resin molded product shape | molded with the vacuum forming apparatus which concerns on embodiment of this invention, (b) is A2-A2 sectional drawing of the resin molded product shown to (a), ( (c) is A3-A3 sectional drawing of the resin molded product shown to (a).

  A resin molded product 10 shown in FIG. 1A is formed by transferring a moldable resin sheet to a mold using a hollow pipe through which a wire is inserted, and then drawing the wire. is there. The resin molded product 10 is integrally provided with a box-shaped base portion 10a having an open top surface, and plate-like (rectangular) ribs 10b standing vertically to the bottom surface at the center of the bottom surface of the base portion 10a. . The erected rib 10b is separated from the side surface of the base 10a.

  Further, referring to FIGS. 1B and 1C, the rib 10b has side spaces 10c, 10c in the vertical direction of the rib 10b each having a hollow space 10k, and the upper side portion 10d in the horizontal direction is a hollow space. 10f. The hollow spaces 10k, 10k, and 10f communicate in a cylindrical shape. The part surrounded by the cylindrical shape of the side part 10c and the upper part 10d is a flat plate part 10e. In this way, the rib 10b is light and high in strength by having a cylindrical shape surrounding the outer periphery of the flat plate portion 10e.

FIG. 2 shows the configuration of a vacuum forming apparatus for forming the resin molded product 10. FIG. 2A is a front sectional view showing a configuration of a vacuum forming apparatus for molding a resin molded product according to an embodiment of the present invention, and FIG. 2B is a side sectional view of the vacuum forming apparatus.
A vacuum molding apparatus 20 shown in FIGS. 2A and 2B includes a rectangular parallelepiped mold body 20a having an upper surface and a lower surface that are the same shape as the planar bottom surface of the base portion 10a of the resin molded product 10 (see FIG. 1). By projecting the four side surfaces of the main body 20a in the vertical direction and surrounding the four sides without any gaps, the four vertical frames 20d forming the recesses 20b and 20c above and below the mold body 20a and the lower recess 20c are closed and closed. And a horizontal plate 20e constituting the space 20h.

  The mold body 20a is linearly bridged between the two hollow pipes 20f standing up and down through the upper and lower surfaces at a predetermined distance from the center of the mold body 20a, and the upper ends of the hollow pipes 20f. And a wire 20i inserted and held in each hollow pipe 20f. The hollow pipe 20f may be an elongated cylindrical shape that penetrates from one end to the other end, such as a cylindrical shape or a rectangular tube shape. The wire 20i preferably has a circular cross section, but the cross section may have another shape such as an ellipse or a polygon.

  As for the wire 20i, both ends of the wire 20i are respectively inserted from the upper end openings of the hollow pipes 20f and are pulled out to the lower end openings, and the respective ends thus pulled out are pulled in the opposite directions. As a result, the hollow pipe 20f is bridged linearly at the upper end, and is held in a state where a predetermined tension is applied to the wire 20i by a wire holding portion (not shown). Depending on the weight and flexibility of the wire 20i and the interval between the upper ends of the hollow pipes 20f, the wire 20i may be stretched linearly on the upper ends of the hollow pipes 20f by its own weight without using a wire holding portion. is there.

  The rib forming portion 20j is configured by the two hollow pipes 20f that are erected and the wire 20i that is stretched linearly around the upper ends of the hollow pipes 20f. It should be noted that the wire 20i may be automatically inserted and bridged into each hollow pipe 20f by a robot arm or the like (not shown).

  Furthermore, in the vacuum forming apparatus 20, a molding die 20g is configured by the four-side inner surface of the upper concave portion 20b, the upper surface of the mold body 20a, and the rib forming portion 20j. Further, a suction port 25a of the vacuum pump 25 is penetrated below the vertical frame 20d so that the airtightness of the closed space 20h is not impaired. By performing vacuum suction with the vacuum pump 25, the closed space 20h becomes negative pressure, and air suction is performed through a plurality of suction holes 26 formed so as to penetrate the mold body 20a in the vertical direction. Note that the transfer means of this claim is constituted by the vacuum pump 25 and the like.

  That is, a resin sheet {see the resin sheet 30 in FIG. 3A} is set so as to cover the opening of the mold 20g, and then vacuum suction is performed by the vacuum pump 25, whereby suction is performed through the suction hole 26. By this suction, the resin sheet is attracted and transferred to the mold 20g. After the transferred resin sheet 30 is cooled and hardened, the wire 20i is released from the wire holding portion and pulled out from each hollow pipe 20f, and the cured resin sheet 30 is removed from the molding die 20g. See) is completed. The resin sheet 30 may be set automatically by a robot arm (not shown) or the like.

  In addition, control of insertion and bridging of the wire 20i to each hollow pipe 20f by a robot arm (not shown), control of setting of the resin sheet 30 to the molding die 20g, and start and stop of vacuum suction by the vacuum pump 25 The operation is controlled by a control device (not shown). This control device includes storage means such as a CPU (Central Processing Unit) (not shown), ROM (Read Only Memory), RAM (Random Access Memory) and HDD (Hard Disk Drive), for example, and the CPU writes to the storage means. The above-described control is performed by executing the program.

<Operation of Embodiment>
Next, the operation | movement at the time of shape | molding the resin molded product 10 with the vacuum forming apparatus 20 of this embodiment is demonstrated with reference to FIGS.

  However, control of insertion and bridging of the wire 20i to each hollow pipe 20f by a robot arm (not shown), control of setting of the resin sheet 30 to the mold 20g, and activation of vacuum suction by the vacuum pump 25 and It is assumed that the stop operation is controlled by a control device (not shown). The hollow pipe 20f has a cylindrical shape, and the wire 20i has a circular cross section that can be inserted into the hollow pipe 20f.

  First, as shown in FIG. 2 (a), both ends of the wire 20i are gripped by the robot arm, and both ends of the wire 20i are inserted from the upper end openings of the respective hollow pipes 20f so as to come out to the lower end openings. . Each of the detached ends is pulled in the opposite direction by the robot arm, and is stretched linearly over the upper ends of the hollow pipes 20f, and in a state where a predetermined tension is applied, the wire 20i is applied by a wire holding portion (not shown). Hold.

  As a result, the rib forming portion 20j is set on the forming die 20g, and as shown in FIG. 3 (a), the resin sheet 30 is placed and set on the upper opening of the forming die 20g by the robot arm. With this set, the opening of the mold 20g is covered with the resin sheet 30. For the resin sheet 30, for example, a thermoplastic resin such as polyethylene or polypropylene is used.

  Next, when vacuum suction is performed by the vacuum pump 25, the closed space 20h becomes negative pressure, and the inside of the mold 20g covered with the resin sheet 30 is sucked through the suction hole 26 of the mold body 20a. The By this suction, the resin sheet 30 is attracted to the molding die 20g as shown in FIG. 3B, and then the resin sheet 30 is attracted and transferred to the molding die 20g as shown in FIG. 3C. After this transfer, vacuum suction is stopped.

  At this time, the resin sheet 30 is also transferred to the rib forming portion 20j erected at the central portion of the mold 20g, and this transferred portion is erected in a rectangular shape. The rectangular standing portion formed by the resin sheet 30 has a hollow pipe 20f wrapped around the side and a wire 20i wrapped around the top. For this reason, the outer peripheral part which connected the side part and the upper part was raised in the cross-sectional circular shape. The inner portion surrounded by the outer peripheral portion has a flat plate shape in which the resin sheet 30 is directly bonded from both sides. The flat plate portion becomes the flat plate portion 10e of the rib 10b shown in FIG. 1A, and the outer peripheral portion becomes the cylindrical side portion 10c and the upper side portion 10d of the rib 10b.

  Next, as shown in FIG. 4A, after the transferred resin sheet 30 is cured, the wire 20i is released from the wire holding portion, and the wire 20i hanging from the lower end opening of one of the hollow pipes 20f is removed. Pull out with the robot arm. As a result, the wire 20i does not exist on the upper side portion of the rib forming portion 20j, so that a columnar hollow space 10f is formed on the upper side portion.

  Thereafter, if the cured resin sheet 30 is removed from the molding die 20g as shown in FIG. 4B, each hollow pipe 20f is pulled out from the rib molding portion 20j. A space 10k is formed. Thereby, hollow spaces (cavities) 10k and 10f communicating with the side part 10c and the upper side part 10d of the rib 10b are formed and become cylindrical. As a result, the base portion 10a and the rib 10b erected on the base portion 10a are integrally molded, and the resin molded product 10 in which the side portion 10c and the upper side portion 10d of the rib 10b communicate in a cylindrical shape is obtained.

<Effect of embodiment>
As described above, the vacuum forming apparatus 20 of the present embodiment has a mold 20g that transfers and molds the moldable resin sheet 30, and a bottom portion of the mold 20g that is spaced a predetermined distance from the bottom of the mold 20g. Rib forming part 20j comprising two hollow pipes 20f standing upright and wires 20i inserted into the hollow pipes 20f and spanned over the upper ends of the hollow pipes 20f, and set in a mold 20g A vacuum pump 25 that sucks the resin sheet 30 and transfers it to the forming die 20g and the rib forming portion 20j is provided. Then, vacuum suction is performed by the vacuum pump 25 to transfer the resin sheet 30 to the molding die 20g and the rib molding portion 20j, and then the wire 20i is pulled out from the two hollow pipes 20f.

  According to this configuration, after the resin sheet 30 is transferred to the molding die 20g and the rib molding portion 20j, the wire 20i is pulled out from each hollow pipe 20f of the rib molding portion 20j erected on the bottom of the molding die 20g. As a result, a hollow space (cylinder space) 10f where the wire 20i is present is formed in the upper side portion 10d of the rib 10b formed by the resin sheet 30 formed by the rib forming portion 20j. Furthermore, if the cured resin sheet 30 is removed from the mold 20g, the hollow pipes 20f on both sides are pulled out from the ribs 10b formed by the resin sheet 30. Thereby, the hollow space (cylinder space) 10k of the extraction trace is formed in the side part 10c of the rib 10b.

  Thereby, hollow spaces (cavities) 10k and 10f communicating with the side part 10c and the upper side part 10d of the rib 10b are formed and become cylindrical. Since the cylindrical shape has a large force against the pressure from the outside, the strength of the rib 10b can be increased. Moreover, since the outer peripheral part of the rib 10b is a cylinder and is hollow, the rib 10b can be reduced in weight. For this reason, the rib 10b erected integrally with the base 10a of the resin molded product 10 can be molded with light weight and high strength.

<Modification of Embodiment>
The resin molded product molded by the vacuum molding apparatus 20 of the above embodiment is not limited to the resin molded product 10, but may be any other as long as it is integrally provided with a base and a rib standing on the base. The shape may also be

  In the above embodiment, a mold release agent may be applied to the wires 20i before the wires 20i are inserted through the hollow pipes 20f. By applying a release agent to the wire 20i, the wire 20i can be easily inserted into each hollow pipe 20f, and when the wire 20i is pulled out, the wire 20i is easily pulled out. For this reason, since the wire 20i can be smoothly pulled out from the upper side portion 10d of the rib 10b, it is possible to prevent problems such as the wire 20i being caught on the inner surface of the upper side portion 10d and damaging the rib 10b.

  Moreover, you may provide the temperature control means which has a heater and cooling device which are not shown in the inside of the type | mold main body 20a, ie, the bottom part of the shaping | molding die 20g. The temperature adjusting means heats or cools the mold body 20a to adjust the temperature, thereby heating or cooling the mold surface of the mold 20g and heating or cooling the resin sheet 30 set in the mold 20g.

  When using the resin sheet 30 of such a thermoplastic resin, the resin sheet 30 is heated in advance at a predetermined temperature to be ready for molding. Moreover, it is preferable to heat the temperature of the molding die 20g to a predetermined temperature by the temperature adjusting means. This treatment facilitates the molding of the resin sheet 30.

  If the resin sheet 30 is set on the molding die 20g under this condition, and the vacuum pump 25 performs evacuation as described above, the resin sheet 30 can be quickly adsorbed to the molding die 20g and transferred without gaps. Thereafter, if the mold 20g is cooled by the temperature adjusting means, the resin sheet 30 can be quickly cooled and cured.

  Although the embodiments and modifications of the present invention have been described above, design changes can be made as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Resin molded product 10a Base part 10b Rib 10c Side edge part 10d Upper side part 10e Flat plate part 10f, 10k Hollow space 20 Vacuum forming apparatus 20a Type | mold main body 20b, 20c Recessed part 20d Vertical frame 20e Horizontal flat plate 20f Hollow pipe 20g Molding mold 20h Closed space 20i Wire 20j Rib forming part 25 Vacuum pump 25a Inlet 26 Suction hole

Claims (4)

A mold for transferring and molding a moldable resin sheet;
Two hollow pipes standing up and down at a predetermined distance from the bottom of the molding die and wires inserted into the hollow pipes and spanned from the upper ends of the hollow pipes. A rib molding part;
Transfer means for transferring the resin sheet set in the molding die to the molding die and the rib molding part, and
A vacuum forming apparatus, wherein after the resin sheet is transferred by the transfer means, a wire is pulled out from the two hollow pipes.   2. The vacuum forming apparatus according to claim 1, wherein a release agent is applied to the wire before the wire is inserted into the two hollow pipes.   The apparatus further comprises temperature adjusting means for heating the mold before transferring the resin sheet to the mold and cooling the mold after the resin sheet is transferred to the mold. The vacuum forming apparatus according to 1 or 2. A base and a rib standing on the base are integrally formed,
The rib has a flat plate portion, a pair of side portions formed on both sides of the flat plate portion, and an upper side portion connecting the tips of the side side portions,
A resin molded product characterized in that a hollow space communicating with the pair of side portions and the upper side portion is formed.

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